1. Field of the Invention
This invention relates to a novel gasoline-soluble polyoxyalkylene diamine compound, to a concentrate comprising the polyoxyalkylene diamine dissolved in a hydrocarbon solvent, and to a haze-free, ORI-inhibited and deposit-resistant motor fuel composition comprising the polyoxyalkylene diamine. More particularly, this invention relates to: (i) a novel polyoxyalkylene diamine compound containing block copolymers with polyoxyalkylene backbones; (ii) a concentrate comprising the novel polyoxyalkylene diamine dissolved in a hydrocarbon solvent; and (iii) a motor fuel composition comprising the novel polyoxyalkylene diamine. Motor fuel compositions comprising the polyoxyalkylene diamine of the instant invention are haze-free, ORI-inhibited, and have a reduced tendency to form deposits. Motor fuel compositions of the instant invention may additionally comprise a polymer/copolymer component.
Combustion of a hydrocarbonaceous motor fuel in an internal combustion engine generally results in the formation and accumulation of deposits on various parts of the combustion chamber as well as on the fuel intake and exhaust systems of the engine. The presence of deposits in the combustion chamber seriously reduces the operating efficiency of the engine. First, deposit accumulation within the combustion chamber inhibits heat transfer between the chamber and the engine cooling system. This leads to higher temperatures within the combustion chamber, resulting in increases in the end gas temperature of the incoming charge. Consequently, end gas auto-ignition occurs, which causes engine knock. In addition, the accumulation of deposits within the combustion chamber reduces the volume of the combustion zone, causing a higher than design compression ratio in the engine. This, in turn, also results in serious engine knocking. A knocking engine does not effectively utilize the energy of combustion. Moreover, a prolonged period of engine knocking will cause stress fatigue and wear in vital parts of the engine. The above-described phenomenon is characteristic of gasoline powered internal combustion engines. It is usually overcome by employing a higher octane gasoline for powering the engine, and hence has become known as the engine octane requirement increase (ORI) phenomenon. It would therefore be highly advantageous if engine ORI could be substantially reduced or eliminated by preventing deposit formation in the combustion chamber of the engine.
An additional problem common to internal combustion engines relates to the accumulation of deposits in the carburetor which tend to restrict the flow of air through the carburetor at idle and at low speed, resulting in an overrich fuel mixture. This condition also promotes incomplete fuel combustion and leads to rough engine idling and engine stalling. Excessive hydrocarbon and carbon monoxide exhaust emissions are also produced under these conditions. It would therefore be desirable from the standpoint of engine operability and overall air quality to provide a motor fuel composition which minimizes or overcomes the above-described problems.
Deposit-inhibiting additives for use in motor fuel compositions are well known in the art. However, conventional additives may cause hazing of the motor fuel. Hazy motor fuels are unacceptable by the public since they may indicate a problem with the fuel, such as the presence of undesired contaminants. It would therefore be desirable to provide a haze-free motor fuel composition which is deposit-resistant and ORI-inhibited.
The instant invention discloses a novel gasoline-soluble polyoxyalkylene diamine compound which, when employed in a motor fuel composition, minimizes the tendency of the motor fuel to form deposits. Consequently, engine ORI is substantially reduced by employing the polyoxyalkylene diamine of the instant invention in motor fuel compositions. Motor fuel compositions of the instant invention are also haze-free, clear, and stable.
2. Information Disclosure Statement
Co-assigned U.S. patent application Ser. No. 000,230, filed Jan. 1, 1987, discloses a novel gasoline-soluble reaction product and the use of the reaction product as an ORI-inhibitor in motor fuel compositions. The novel reaction product is obtained by reacting:
(i) about 1 mole of a dibasic acid anhydride; PA0 (ii) 1-2 moles of the novel polyoxyalkylene diamine of the instant invention; and PA0 (iii) 1-2 moles of a hydrocarbyl polyamine. PA0 (i) reacting a dibasic acid anhydride with a polyoxyisopropylenediamine of the formula ##STR1## where x is a numeral of about 2-50, thereby forming a maleamic acid; (ii) reacting said maleamic acid with a polyalkylene polyamine, thereby forming a condensate product; and PA0 (iii) recovering said condensate product.
Co-assigned U.S. Pat. No. 4,581,040 teaches the use of a reaction product as a deposit inhibitor additive in fuel compositions. The reaction product taught is a condensate product of the process comprising:
Co-assigned U.S. Pat. No. 4,659,336, filed on Mar. 28, 1986 discloses the use of the mixture of: (i) the reaction product of maleic anhydride, a polyether polyamine containing oxyethylene and oxypropylene ether moieties, and a hydrocarbyl polyamine; and (ii) a polyolefin polymer/copolymer as an additive in motor fuel compositions to reduce engine ORI.
Co-assigned U.S. Pat. No. 4,659,337, filed on Jan. 23, 1986 discloses the use of the reaction product of maleic anhydride, a polyether polyamine containing oxyethylene and oxypropylene ether moieties, and a hydrocarbyl polyamine in a gasoline motor fuel to reduce engine ORI and provide carburetor detergency.
U.S. Pat. No. 4,604,103 discloses a motor fuel deposit control additive for use in internal combustion engines which maintains cleanliness of the engine intake system without contributing to combustion chamber deposits or engine ORI. The additive disclosed is a hydrocarbyl polyoxyalkylene polyamine ethane of molecular weight range 300-2500 having the formula ##STR2## where R is a hydrocarbyl radical of from 1 to about 30 carbon atoms; R' is selected from methyl and ethyl; x is an integer from 5 to 30; and R" and R"' are independently selected from hydrogen and --(CH.sub.2 CH.sub.2 NH--).sub.y H where y is an integer from 0-5.
U.S. Pat. No. 4,357,148 discloses the use of the combination of an oil-soluble aliphatic polyamine component containing at least one olefinic polymer chain and having a molecular weight range of 600-10,000, and a polymeric component which may be a polymer, copolymer, hydrogenated polymer or copolymer, or mixtures thereof having a molecular weight range of 500-1500 to reduce or inhibit ORI in motor fuels.
U.S. Pat. No. 4,191,537 discloses the use of a hydrocarbyl polyoxyalkylene aminocarbonate, having a molecular weight range of 600-10,000 and also having at least one basic nitrogen atom per aminocarbonate molecule, to reduce and control ORI in motor fuels.
Co-assigned U.S. Pat. No. 3,502,451 discloses the use of C.sub.2 -C.sub.6 polyolefin polymers or hydrogenated polymers having a molecular weight range of 500-3500 in motor fuels to eliminate or reduce deposition on the intake valves and ports of an internal combustion engine.
U.S. Pat. No. 3,438,757 discloses the use of branched chain aliphatic hydrocarbyl amines and polyamines having molecular weights in the range 425-10,000 to provide detergency and dispersancy in motor fuels.
Co-assigned Rep. of South Africa Appl. No. 731911, filed on Mar. 19, 1973, discloses a motor fuel composition comprising a polymeric component which is a polymer or copolymer of a C.sub.2 -C.sub.6 unsaturated hydrocarbon having a molecular weight in the range 500-3500, and a hydrocarbyl-substituted amine or polyamine component, said motor fuel composition having effectiveness in reducing engine intake valve and port deposits.
Co-assigned U.S. Pat. No. 4,316,991 discloses a modified polyol compound having a molecular weight range of 2000-7000, produced by reacting an initiator having an active hydrogen functionality of 3-4, one or more alkylene oxides, and an epoxy resin.
U.S. Pat. No. 3,654,370 discloses a method of preparing polyoxyalkylene polyamines by treating the corresponding polyoxyalkylene polyol with ammonia and hydrogen over a catalyst prepared by the reduction of a mixture of nickel, copper, and chromium oxides. The polyoxyalkylene polyamines formed are of the formula ##STR3## wherein R is the nucleus of an oxyalkylation-susceptible polyhydric alcohol containing 2-12 carbon atoms and 2-8 hydroxyl groups, Z is an alkyl group containing 1-18 carbon atoms, X and Y are hydrogen or Z, n has an average value of 0-50 and m is an integer of 2-8 corresponding to the number of hydroxyl groups in the polyhydric alcohol.
U.S. Pat. No. 3,535,307 discloses the preparation of high molecular weight polyether block copolymers by the sequential alkoxylation of a polyfunctional initiator with alkylene epoxide components.